Grab-bucket-operating mechanism for cranes.



H. SAWYER. GRAB BUCKET OPERATING MECHANISM FOR CRANES.

APPLICATION FILED IANIZYI 1912.-

Patented Oct. 26, 1915.

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H. SAWYER.

GRAB BUCKET OPERATING MECHANISM FOR CRANES.

APPLICATION FILED IAN-27,1912.

Patented Oct. 26, 1915.

3 SHEETSSHEET 2 H. SAWYER.

GRAB BUCKET OPERATING MECHANISM FOR CRANES.

APPLICATION FILED JAN.27. I912.

Patented Oct. 26, 1915.

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GRAB-BUCKET-OPERATING MECHANISM FOR CRANES.

Specification of Letters Patent.

Patented Oct. 26, 1915.

Application filed January 27, 1912. Serial No. 673,743.

To all to ham it may concern Be it known that 1,,HARRY SAWYER, a citizen of the United States, residing at Muskegon, county of Muskegon, State of Michigan, have made a certain new and useful Invention in Grab Bucket- Operating Mechanism for Cranes, of which the fol lowing is a specification.

This invention relates to operating mechanism for the grab buckets of hoisting cranes, such as are employed for loading and unloading coal or other materials.

The object of the invention is to provide a construction of operating mechanism of the character referred to, which is simple, ei'iicient, economical to manufacture and easy to manipulate and control.

Other objects of theinvention will appear more fully hereinafter.

T he invention consists substantially in the construction, combination, location, and relative relation and arrangement of parts, all as will be more fully hereinafter set forth, as shown. in the accompanying drawings, and finally pointed out in the append-. ed claims.

In the accompanying drawings: Figure l is a view in elevation of a crane structure showing the application thereto of a grab bucket operating mechanism embodying the.

principles of my invention. Fig. 2 is a view partly in longitudinal central section through and partly in elevation of one form of grab bucket operating mechanism embodying the principles of my invention. Fi 3 is a view similar to Fig. 2, showing slightly modified form of operating mechanism embodying my invention. Fig. 4c is a top plan view of the same. Fig. 5 is a View in transverse section on the line 5, 5, Fig. 3. Fig. 6 is a similar view on the line 6, 6, Fig. 3. Fig. 7 is an end view looking from the left of Fig. i. Fig. 8 is a similar View looking from the right of Fig. 4.

In the operation of buckets employed in connection with cranes for loading and unloading coal, grain, ore, or other materials, and particularly in thecase of what are ordinarily called grab buckets, it is usual to employ two or more ropes, chains or other similar devices, (which for brevity, I shall hereinafter refer to as ropes, intending thereby to include any suitable device for the purpose), or two or more sets of ropes, for

the purpose of operating and controlling the bucket.

One of these ropes, indicated at J, Fig. 1, extends downward from the hoisting and operating mechanism, presently to be described through a guide sheave ligand is attached to a drum L, in the bucket, upon which it winds. This rope is called the closing and hoisting rope. By pulling up on the closing and hoisting rope the drum L, is rotated thereby winding up a chain or other suitable connection M upon the hub of drum L, the other end of chain M, being attached to the relatively stationary head N, of the bucket. This operation causes the joint P between the bucket sections R, to be drawn upwardly and said bucket sections to close upon themselves. When the two bucket sections are closed, continued pulling up on the closing and hoisting rope J, causes the entirebucket and its frame to be elevated. Another rope S, (or if desired two ropes may be employed,) is attached to the bucket head N, and is called the holding and lowering rope. The function of the holding and lowering rope or ropes is to receive the weight of the bucket when it is desired to dump it, thereby enabling the bucket portions R, to open up when the pull on the closing and hoisting rope J is released. It is obvious that while the closing and hoisting rope is in operation to hoist the bucket the holding and lowering rope or ropes S should alsobe taken or wound up so as to prevent the same from becoming slack, and hence so as to permit it to be ready at any instant to perform its function of receiving the weight of the bucket when it is required to dump said bucket and to again lower the bucket for another load. By throwing the weight of the bucket and its load onto the holding and lowering rope S, and then releasing the closing and hoisting rope from its hoisting mechanism, the chain M is permitted to unwind from the hub of drum L the joint P is lowered and the bucket sectionsR, swing apart into open relation to dump the con tents thereof.

The closing and hoisting rope as well as the holding and lowering rope may be made in duplicate, if desired. It is quite customary, however, to employ a single closing and hoisting rope, which has the arrangement function and operation as above described and to employ two holding and lowering ropes, one attached at or near each end of the bucket head and on respectively opposite sides of the closing and hoisting rope,

thus bringing the three ropes into substantially the same vertical plane with the closing and hoisting rope in the center. This arrangement serves to prevent the bucket from rotating or sluing around while being hoisted or transported bythe crane mechanism. Many other types of construction and arrangement of apparatus of this class and nature are familiar to persons skilled in this art and as the present invention does not reside in the .construction and arrangement as above described of the bucket and the manner of connection of the closing and hoisting and the holding and lowering ropes to the'bucket, but only to the mechanism employed for operating and controlling said ropes, it is believed that the foregoing description is sufficient to illustrate the objects and purposes of my invention as will now be described, it being understood that my invention is not to be limited or restricted in respect to any specific construction of bucket, nor to any particular number of ropes employed in connection with the bucket, nor to the manner of connecting said ropes to the bucket.

The bucket hoisting and controlling mechanism, indicated generally at H, Fig. 1, and with which the present invention is chiefly concerned, may be mounted on any suitable or convenient construction and arrangement of traveling overhead crane beam, in the usual manner, and operated by any suitable arrangement of power motors.

In Figs. 2 to 8, I have shown in detail various arrangements and constructions of bucket rope operating and controlling mechanisms embodying the principles of my invention. In its essential characteristics it includes drums on which the various bucket ropes are wound, and from which they are unwound, in the operation of the apparatus. It also includes clutch and brake mechanism for throwing said drums into and out of action as required, and means for driving said drums and for controlling said clutches and brake.

In the particular form shown, a drum C for the closing and hoisting rope and drums F, F, for the holding and lowering ropes, are employed. Also a drive gear A, and a brake strap and drum G, with clutch devices B, E, andfriction device D, for coupling up these various drums. The clutch B'serves, when operated to couple the drive gear A to the hoisting drum C, while the clutch E, and friction device D, are employed to couple the drums C and F, F, together. The drums F, F, the brake drum G, the drum C, and the'drive gear A, are all mountedupon the same shaft, so as to 013+ erate in concentric relation with respect to the same axis. In the arrangement shown in Fig. 2, the shaft 10, is hollow, and the clutches are controlled by means of levers 11, 12, operating on rods 13, 14:, which extend longitudinally through the shaft and are connected to the sliding collars 15, 16, of the clutch devices.

In Fig. 3, the shaft 22 is solid and while the gear,'brake and rope operating and con trolling drums are arranged on said shaft in the same relation and relative arrangement, the clutch devices are operated by levers 17 18, having fork arms 19, which straddle the collars 20, 21, placed on the shaft 22, outside the drums F, and between said drums and the bearings for the shaft 22. These collars are connected by rods 23, 2 1 to collars 25, 26, mounted on shaft 22, and to which are connected the arms of toggle links 27, 28 to the other ends of which are connected levers 29, 30, through which the movable member 31 of the clutch devices is operated. The clutch device, in this instance, is shown as of the flexible band type. The two arms or levers 29, 30, of each clutch device are connected together by a rod or link 32, to prevent any tendency of the clutch operating collars to bind or cramp on the shaft along which they slide in the operation thereof.

lVhile I have shown and described a specific form of clutch device and a form which in practice, I have found well adapted to the purposes of my invention, it is to be understood that in its broadest scope, my invention, as defined in the claims, is not to be limited or restricted to any specific construction of clutch devices.

In the form of clutch mechanism shown the levers 11, 17, control the clutch which couples the gear A to the drum C, while the levers 12, 18, control the clutch which conples the drum C to rotate with the drums F, Iv

and the brake drum G. The drums F and G are mounted to rotate with shaft 10, while the gear A and drum C, turn loosely on said shaft.

The strap of brake drum G, is secured to the frame of the trolley which carries the several devices referred to and serves to lock the brake drum to the frame.

The device D, see Fig. 3, is preferably a friction device, and serves to frictionally connect the drums F to the drum C with su fficient force to cause the holding and lowering ropes to be coiled up on said drums F, when the drum 0 is operating to coil up thereon the closing and hoisting rope in elevating the bucket.

It will be understood that the holding rope must begin to wind up the instant the bucket begins to rise, or else said rope will become slack. The friction device D serves to accomplish this purpose. Without said device it would be necessary to throw in the clutch E the instant the bucket is closed and commences to hoist. By providing both the friction device D, and the clutch E, I provide for taking up the slack of the holding rope, as above explained, without throwing the clutch E into operation, and I also provide sufficient power through the operation of the clutch E to take the load when neces sary, the friction device not being sufficient for such purpose.

The strap 34 of brake drum G, is controlled by a lever 35, see Fig. 5.

For economy in manufacture one member of each of the clutch devices B, E, may be formed integrally with the gear-A and brake drum G, respectively, or with the hoisting drum C. This however, is not essential. In Fig. 2, I have shown the drum member of clutches B and E bolted to. the ends of the drum C while in Fig. 3, I have shown said members formed integrally with the ends of drum C, by enlarging said ends.

The operation of the-apparatus is very simple, and the control thereof is easily effected. a

Assuming that the bucket is lowered onto a pile of coal, for instance, and the parts It, thereof to be open, as shown in Fig. 1, and

the apparatus otherwise in condition ready,

to be operated. The clutch B is now operated to couple gear A to drum C, and the clutch E is operated to uncouple drums F, from drum 0. The motor which drives gear A is then put into operation and the closing and hoisting rope J is thereby coiled up on drum C. The first action resulting from the coiling up of this rope is to close the members R, of the bucket upon each other, as above explained, and thereafter the closed bucket with its load is elevated by the continued coiling up of rope J upon drum C. As soon as the pull on rope J is suflicient to cause the bucket to begin to rise the holding and lowering ropes begin to wind onto drums F, through the frictional drive of said drums, from drum C through the fI'lC': tion device D, the friction pull of which be ing adjusted so as to be just suflicient to coil up the slack in said holding and lowering ropes without exerting any substantial pull on said ropes, or through them on the bucket. The bucket is thus closed and hoisted and may then be transported together with its load by the supporting trolley and crane beam to any desired point within the range of operation of thecrane, and, if desired, then lowered, by merely controlling the various motors employed to operate the apparatus. When it is desired to empty or dump the bucket, the holding brake G is applied thereby locking the drums F against rotation. Then the hoisting motor is operated in the lowering direction, thereby revolving drum C, in a direction to unwind the closing and hoisting rope J, therefrom. This action transfers the weight of the bucket and its load onto the holding and lowering ropes S, while at the same time permitting the chain M to unwind from the hub of drum L thereby permitting gravity material resistance to the dumping operation. When the load has been discharged the clutch E, is operated to couple the drums F to rotate with drum 0, said clutch E, up to this time having remained unclutched. The motors by which gear A, and the crane and the trolley are driven may then operate in a direction to hoist the open bucket if desired andto transport the same while still maintained in its open position, as may be desired. When it is desired to again lower the bucket upon the pile of material to be handled, clutches B and E being applied, as above noted, the brake Gr is released and the hoisting motor is run in lowering direction. If it is desired to lower the bucket rapidly so as to save time or to cause the open bucket open sections of the bucket to some extent into the pile of material, the clutch B is released, thereby uncoupling gear A, from drum C, and the rest of the apparatus carried by the supporting shaft. The brake G is then gradually released, as desired, thereby letting the bucket down by gravity, its speed of descent being controlled as desired by the brake Gr. After the bucket is thus lowered the clutch E, is again released and theapparatus is ready for the application of the clutch B for another cycle of operation.

and G, should be so attached or connected as to rotate together, and a convenient way of accomplishing this 1s shown wherein these drums are all mounted to rotate with the able distance apart, but the arrangement shown, wherein these drums are mounted to rotate with the supporting shaft and the drum C, and its driving gear A are loose on the shaft, the separation of said drums F, is permitted while, at the same time, they are mounted to rotate together. This arrange ment also permits the drum C, and its driving gear A, to rotate independently of the drums F, and still be supported upon the same shaft therewith, said drum C, and its driving gear being mounted to rotate freely on said shaft. This also permits the gear A, to rotate independently of drum G, and of the drums F, and G. The manner of mounting this gear A upon the shaft is not It will be observed that the drums F, F,-

grab bucket controlling and operating ropes drum C, though this is not an essential characteristic of my invention.

The location upon the shaft of the collars 20, 21, is. not of material consequence.

While, therefore, I have shown these collars mounted outside the drums F, in order .to

bring the drums F, nearer together, I do not wish to confine myself to this particular location of said collars.

By thus mounting the several parts of the rope operating and controlling apparatus side by side and in axial alinement with each other, I am enabled to dispense with counter shafts and connections which increase the complication and expense of the apparatus, while at the same time, I am enabled to secure amore effective, convenient, direct and satisfactory control of the various operations.

It will be seen that by employing the two levers29, 30,,and the link 32 for connecting them to move in unison, for operating the clutch devices, I am enabled to avoid cramping'and sidewise pressure of the clutch operating collars as they are slid along the shaft to apply the clutches. It'will also be seen that the clutch operating levers operate on the principle of toggles, and hence Whenoperated to apply the clutches they remain in applied position without requiring continued application of power to the operating levers.

Having now set forth the object and nature of my invention, and illustrative constructions embodying the principles thereof, and having explained the same and their purposes, functions and mode of operation thereof, what I claim as new and useful, and of my own invention, and desire to secure by Letters Patent, is

1. In a hoisting mechanism, the combination with a supporting shaft, of a plurality of drums mounted thereon in axial alinement with each other, means for driving one of said drums including a clutch mechanism, an automatic friction drive and an independent clutch device connection intermediate said driven drum and an adjacent drum, means for operating said clutch device, and

actuatedby said drums. v

2-. In a hoistlng' mechanism, the combination with operating drums for grab bucket controlling ropes, arranged in axial alinement with each other of meansarranged in axial alinement with said drums for driving one of them, said means including a clutch mechanism, and a manually operable clutch mechanism and also an independent automatic friction mechanism intermediate said driven drum and an adjacent drum.

3. In a hoisting mechanism, the combination with operating drums for grab bucket controlling ropes, arranged in axial alinement with each other of means including a manually operable clutch for driving one of said drums, an independent manually operable clutch mechanism intermediate said driven drum and an adjacent drum, and an independent automatic friction drive connection also arranged intermediate said driven drum and'said adjacent drum.

4:. In a hoisting mechanism, the combina tion with a supportng shaft, of a series of drums mounted thereon in axial alinement with each other, means also mounted on said shaft, and including a clutch mechanism for driving one of said drums, means for operating said clutch mechanism, an independently controllable clutch mechanism mounted on said shaft intermediate said driven drum and an adjacent drum, and an auto matic friction drive connection intermediate said driven drum and said adjacent drum.

5. In a hoisting mechanism, the combination with a supportng shaft, of drums for operating grab bucket controlling and actuating ropes. said drums being moimted on said shaft in line With each other, one of said drums being loose on said shaft, and another mounted to rotate with said shaft, means also mounted on said shaft and including a clutch mechanism for driving ti o loosely mounted drum, means for operating said clutch mechanism and independently controllable clutch mechanism intermediate said loosely mounted and said other drums.

6. In a hoisting mechanism, the combination with a supporting shaft. of grab bucket actuating rope operating drums mounted thereon in axial alinement with each other, a drive gear loosely mounted on said shaft, clutch devices intermediate said gear and one of said drums, means for operating said clutch devices, a brake drum mounted on said shaft to rotate therewith, independently operable clutch devices intermediate said driven drum and said brake drum, coupling connections between said brake drum and the other of said rope drums, and a locking band cooperating with said brake drum.

7. In a hoisting mechanism, a shaft, a closing and hoisting drum loosely mounted thereon, holding and lowering drums mounted to rotate with said shaft and respectively located on opposite sides of the closing and hoisting drum, a drive gear loosely mounted upon said shaft, a clutch intermediate said drive gear and closing and hoisting drum, an independent clutch intermediate the closing and hoisting drum and one of the holding and lowering drums, and a brake drum. said brake drum and also said last mentioned clutch being mounted on said shaft, said brake drum being mounted to rotate with said shaft.

8. In a hoisting mechanism, a. shaft, a

closing and hoisting drum loosely mounted thereon, holding and lowering drums mounted to rotate with said shaft and respectively located on opposite sides of the closing and hoisting drum, a drive gear for said closing and hoisting drum, a clutch intel-mediate the closing and hoisting drum and one of the holding and lowering drums, and a brake drum, said brake drum and also 1 said clutch being mounted on said shaft,

witnesses, on this 12th day of Jan., A. D., 15

HARRY SAWYER. Witnesses J. G. EMERY, J12, OTTO ALBERT.

Copies of this patent may be obtained for five cents each, by addressing the Gommissioner of Patents, Washington, D. G. 

